1. Field of the Invention
The invention relates to a gas conversion process including synthesizing and hydroconverting hydrocarbons, wherein synthesis gas hydrogen and hydroconversion tail gas hydrogen are used in the process. More particularly, the invention relates to a gas conversion process comprising synthesizing hydrocarbons from a synthesis gas and hydroconverting the synthesized hydrocarbons with hydrogen produced from the synthesis gas, wherein the hydroconversion produces a tail gas rich in hydrogen which is used for one or more of the hydrocarbon synthesis, rejuvenation of the synthesis catalyst, hydrogen production, and hydrodesulfurizing well gas condensate.
2. Background of the Invention
Hydrocarbon synthesis processes are known in which a synthesis gas feed comprising a mixture of H.sub.2 and CO is fed into a hydrocarbon synthesis reactor in which it reacts in the presence of a Fischer-Tropsch catalyst under conditions effective to form higher molecular weight hydrocarbons. These processes include fixed bed, fluid bed and slurry hydrocarbon synthesis, all of which are well documented in various technical articles and in patents. In many cases it is desired that the synthesized hydrocarbons comprise mostly C.sub.5+ hydrocarbons (e.g., C.sub.5+ -C.sub.200) and preferably C.sub.10+ hydrocarbons, at least a portion of which are solid at standard conditions of room temperature and pressure. It is preferred in a slurry hydrocarbon synthesis process that the hydrocarbons comprise mostly C.sub.5+ paraffins. These hydrocarbons are upgraded to more valuable products by one or more hydroconversion operations in which at least a portion of the molecular structure is changed by reacting with hydrogen. Hydroconversion operations therefore all require hydrogen. Hydrogen is also required for rejuvenating the hydrocarbon synthesis catalyst and sometimes for maintaining or changing the H.sub.2 to CO ratio of the syngas feed for the hydrocarbon synthesis. Further, the production of natural gas from a gas well also produces valuable, sulfur-containing hydrocarbon liquids which need to be hydrodesulfurized to form products. It is desirable to have a hydrocarbon synthesis process in which hydrogen required for the hydrocarbon synthesis catalyst rejuvenation, hydroconversion upgrading of the synthesized hydrocarbons and also hydrodesulfurizing of the well liquids is obtained from within the overall, integrated process or plant itself, rather than depending on an outside source of hydrogen.